Previous attempts at integrating a transceiver on a chip involved using monolithic integration, in which the active elements are formed in the substrate, and are thus all made of the same material. This does not allow optimum performance to be realized for at least one of the detector array and the light source array.
Other attempts have placed the active elements, e.g., the light sources and the detectors, on different substrates. However, this increases the complexity of the system due to an increased number of components and alignment difficulty.